Did you know about Blackle? Blackle is Black version of Google for saving energy, that have a Google search box on a black background with light text. The site is intended to allow environmentally conscious Internet users to save a little electricity while they surf. The concept is based on findings that suggest that some computer monitors use more energy to display a white or light coloured screen than they do to display a black or dark coloured screen.
it said Blackle saves energy because the screen is predominantly black. "Image displayed is primarily a function of the user's color settings and desktop graphics, as well as the color and size of open application windows; a given monitor requires more power to display a white (or light) screen than a black (or dark) screen". - Roberson et al, 2002
On Mark Ontkush blog, entitled: “Black Google Would Save 750 Megawatt-hours a Year”. He said, Google, which has a white background and gets about “200 million queries a day” could reduce global energy use by 750 Megawatt-hours a year by simply changing the color of its homepage to black.
Btw, there is another black Google custom search portal called Jabago.com that designed to reduce eye strain and save energy (with CRT monitors) while conducting Google searches. All searches from this portal will take you directly to google.com with a black background and light text.
In the end, with Black search portal, every time we load our web browser reminds us that we need to keep taking small steps to save energy.